This invention relates to a new and improved lift cover assembly for protecting electrical wiring installations from the entry of liquids.
Lift cover assemblies are used in conjunction with electrical wiring installations having male or female electrical devices mounted thereon to protect the installation against the entry of ambient liquids, particularly rain water.
Such assemblies typically comprise a lift cover pivotally mounted at one end to a mounting plate member mounted stationary against the outer surfaces of an installation box. It is usually desired that the mounting plate and the cover be flat and project only slightly beyond the outer surface of the installation box. From a functional standpoint, an assembly with such a narrow profile is less likely to obstruct or interfere with electrical cords and equipment used near or at the installation. Additionally, an assembly with a narrow profile is less obtrusive than one with a thicker profile and is therefore more esthetically acceptable to many users.
The lift cover is normally biased to a closed position by a coil spring mounted in the lift cover mounting. The lift cover protects the entry of the installation box against impinging liquid sprays when it is closed. The coil spring is designed to be wound up when the cover is raised and unwinds to restore the cover to its closed position when the cover is released. Communicating with the opening in the plate member and located inwardly of the closed cover is the front face of a wiring device. This device is usually a female type of wiring device, such as a female single or duplex receptacle, but it may also be a male type of device, such as an electrical plug. The free end of the lift cover may be raised manually against the bias of the spring to allow access to the front face of the female receptacle to permit insertion of the contacts of the appropriate male plug into the receptacle contacts. When the two devices are interconnected and the lift cover released, the spring unwinds causing the free end of the cover to rotate downward until it rests upon the male plug or upon the cable attached to and extending from the plug.
A circular gasket is typically mounted on the interior surface of prior art lift cover assemblies to abut the surface surrounding the plate opening. The gasket prevents the entry of water into the plate opening and into the receptacle contacts or other parts of the installation when the male plug is disconnected and removed from the receptacle and the cover is in its closed position. The liquids may be derived from rain, seawater spray, lawn sprinkling apparatus or from other ambient sources. Whereas, these prior art assemblies work effectively with the lift cover closed, they do not work nearly as effectively when the lift cover is raised. This is because the seal is raised with the cover and thusly removed from protecting the entry into the plate opening. In such case, it is possible for liquid to flow into the installation box through the opening in the front plate and over the interface between the mutually abutting front faces of the electrical plug and the electrical receptacle. Obviously, this liquid can cause direct corrosion problems. Moreover, the presence of water on the electrical contacts of the intercoupled wiring devices can accelerate the corrosion of the contacts through galvanic action.
Hitherto, the requirement for installations of this type was basically that the installation be shielded by the lift cover assembly from liquids issuing from above the assembly; that is, rain. The protection requirements are, however, becoming more stringent. The lift cover assembly is now required to shield the installation against the ingress of liquid sprays issuing from sources which are positioned below the installation, as well as above. Such sources would, for example, include lawn sprinklers of various types. Whereas this new requirement may be met by lift cover type of installations which project substantially from the surface on which they are mounted, as mentioned above, it is usually considered desirable that the lift cover assembly have a narrow profile from both the functional and esthetic viewpoints. The invention disclosed hereinbelow is intended to meet with these stringent requirements.